Patent attributes
A laborsaving rotation shaft device comprises a base; a first rotation unit; a pair of second rotation units, a first rotation guiding structure is disposed between the second rotation unit and the base, and a second rotation guiding structure is disposed between the second rotation unit and the first rotation unit; a torsion unit, having a connection rod, a friction torsion mechanism is disposed between the connection rod and the first rotation unit; a slide mechanism, including a slide block pivoted to the connection rod and radially formed with at least one slide hole allowing a slide rod to be received, and a spring sleeved on the slide rod; with an energy releasing or energy storing effect provided by the spring, the slide block is able to provide a torsion, which has effects of automatically unfolding and folding assistance, to the first rotation unit.